Folding knife



FIG. 1 is perspective view of the folding knife of my new design;

FIG. 2 is a left side view of the folding knife of my new design;

FIG. 3 is a right side view of the folding knife of my new design,

FIG. 4 is a top view of the folding knife of my new design;

FIG. 5 is a bottom view of the folding knife of my new design;

FIG. 6 is a right end view of the folding knife of my new design; and,

FIG. 7 is a left end view of the folding knife of my new design.

The broken line showings of the fasteners form no part of the claimed design. 

The ornamental design for a folding knife, as shown and described. 